After over 40 years, Harnoncourt's 1968 recording of Bach's liturgical masterpiece still resides in the top part of any list of recommendations. Three of the 5 soloists will be very familiar to Harnoncourt addicts, especially those who have all or many of his portion of Teldec's Cantata cycle. Helen Watts (contralto), Kurt Equiluz (Tenor), and Max van Egmond (baß) shine as one would expect. The two sopranos, Rotraud Hansmann and Emiko Iiyama, are on par with the more well-known solists, and the ensembles are spectacular. Harnoncourt leads a performance that is always sensitive to the vocal lines. It is this sensitivity that, in my opinion, makes this recording "sing" with more clarity and power than recordings by even the most famous and able "traditional" leaders like Klemperer, Karajan, etc. And the choir, the Wiener Sängerknaben (Vienna Boys Choir) under Hans Gillesberger, are equally in fine form though not up to the standard of some other choirs (Herreweghe in particular).
While I would not want to be without several other fine recordings of one my favorite choral works of all time (Herreweghe, Gardiner, and Suzuki come to mind), if I could only have one then I would not be disappointed if it had to be this recording.